Segment Information (Revenues by geographic region) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenues, net	$ 634,646	$ 632,165	$ 2,026,057	$ 1,901,985
United States
Segment Reporting Information [Line Items]
Revenues, net	499,316	512,062	1,616,453	1,548,145
Europe
Segment Reporting Information [Line Items]
Revenues, net	93,356	84,415	290,879	238,357
Other Geographic Locations
Segment Reporting Information [Line Items]
Revenues, net	$ 41,974	$ 35,688	$ 118,725	$ 115,483